lengthen

verb

length·​en ˈleŋ(k)-thən 

ˈlen(t)-

lengthened; lengthening

ˈleŋ(k)th-niŋ,

ˈlen(t)th-;

ˈleŋ(k)-thə- 

ˈlen(t)-

transitive verb

: to make longer

intransitive verb

: to grow longer

lengthener

ˈleŋ(k)th-nər

ˈlen(t)th-;

ˈleŋ(k)-thə- 

ˈlen(t)-

noun

Synonyms

• extend
• prolong
• increase
• stretch
• elongate

Choose the Right Synonym for lengthen

extend, lengthen, prolong, protract mean to draw out or add to so as to increase in length.

extend and lengthen imply a drawing out in space or time but extend may also imply increase in width, scope, area, or range.

extend a vacation

extend welfare services

lengthen a skirt

lengthen the workweek

prolong suggests chiefly increase in duration especially beyond usual limits.

prolonged illness

protract adds to prolong implications of needlessness, vexation, or indefiniteness.

protracted litigation

Examples of lengthen in a Sentence

The days lengthened with the approach of spring.

Proper care will lengthen the life of the engine.

lengthen a pair of trousers

Recent Examples on the Web

Deadhead plants after flowering to lengthen the bloom season. —Kim Toscano, Southern Living, 3 Oct. 2025

But solar advocates pushed back, warning that the changes would lengthen payback periods, discourage solar investment and undermine clean energy goals adopted by cities like Boise. —Angela Palermo, Idaho Statesman, 2 Oct. 2025

When the season was lengthened to include October and November, the hunting improved dramatically. —Worth Matthewson, Outdoor Life, 2 Oct. 2025

The modifications included lengthening the body by 10 inches, lowering it, and giving it a new rear aero kit, as well as a new exhaust setup. —Ben Oliver, Robb Report, 30 Sep. 2025

Word History

First Known Use

14th century, in the meaning defined at transitive sense

Rhymes for lengthen

• strengthen

Kids Definition

lengthen

verb

length·​en ˈleŋ(k)-thən 

ˈlen(t)-

lengthened; lengthening ˈleŋ(k)th-(ə-)niŋ 

ˈlen(t)th-

: to make or become longer

lengthener

ˈleŋ(k)th-(ə-)nər 

ˈlen(t)th-

noun